A tracking control method for series-resonant converters

In this paper, a novel method to provide tracking control for the series-resonant converters (SRC) is originally introduced. The difficulty of achieving stability for the instantaneous cycle-by-cycle current control in the SRC is thoroughly reviewed together with presentation of a remedy for the problem. By inserting a filter stage into the average current-mode control mechanism of the SRC, the system can now be stable and reduced to be a first-order current-control connected in series with a first order calculated delay. The tracking control principle is also introduced and its application into SRC is demonstrated by predicting the output current demand and then feeding that demand back into the cycle-by-cycle average current-control loop. A numerical example is finally presented together with the simulation results.